Furnace and method of conveying materials therethrough



.FUR

H. P. EI'ICCANN.

NACE AND METHOD 0F CONVEYING MATERIALS APPLICATION FILED SEPT. I0, 1919.

THERETHROUGH.

atented Dec. 13, 1921 5 SHEETS-SHEET 2- Arran/ft HAP.l IVIcCANN. FURNACE AND METHOD 0F CONVEYING MATERIALS THERETHROUGH APPLICATION FILED SEPT. I0, 1919.

Patented 136.113,1921.

6 SHEETS-SHEET 3.

.ilII III .4 rra/PNE' Y H. P. IVICCANN.

FURNACE AND METHOD OF CONVEYING MATERIALS THERETHROUGH.

APPLICATION FILED SEPT. I0, |919.l

1,400,367., Patented Dec. 13, 1921A.

6 SHEETS-SHEET 4.

. MCCANN.

FUBNACE AND METHOD 0F CONVEYING MATERIALS THERETHROUGH.

TToef/fx UNITEDY STATES HARRY P. MocANN,

PATENT OFFICE'.

or LAxEwooD, omo.

FURNACE AND METHOD OF CONVEYING MATERIALS THERETHROUGH.

Application led September `treating furnaces through which the materials to be treated are conveyed at such a rate of travel as to permit the heat of the,

furnace'to bring them to the desired condition vbefore they are removed or discharged from the furnace.

Amon the objects of my invention are the provlsion of a furnace in whichthe materials are uniformly and accurately heated as they are conveyed through the furnace; the provision 0f a simple and practical means for conve ing materials through a heated furnace without serious deterioration -of the conveyer mechanism from the action of heat; the provision of an improved method of conveying materials through a furnace; and the provision of means for conveyin separate articles through a ,furnace an maintaining them in regular spaced-apart relation to each other.

These and other objects of my invention are attained by the`use of my invention described herein and illustrated in the accompanying drawings in which- Flgure 1 is a vertical longitudinal section through av furnace embodying my invention;

Fig. 2 is a vertical transverse section on line II-II of Fig. 1;

Fig. 3 is a vertical transverse section on line III- III of Fig. l;

Fig. 4 is a vertical longitudinal section of a modified form of furnace embodying my invention;

Fi 5 is a vertical transverse section on line Vf of Fig. 4; l

1 Fi 6 is a verticaltransverse section on line VI of Fig. 4; I

- Figs. 7, 8, 9 and 10, show the work-movingor conveyer member of the structure shown in Fig. 1 in the different positions Specification of Letters Patent.

Patented Dec. 13, 1921.

1o, 1919. serial No. 323,038.

taken by it in performing its series of movements.

In the preferred embodiment of my in-` vention, as illustrated in Figs. 1, 2 and 3, there is shown a form of conveyer adapted to move the materials, commonly called the work, to be treated through the furnace step by step and to maintain them in regular and orderly spaced-apart relation to each other. To accomplish this desired movement of the work through the furnace I provide a hearth, 1, havinur a longitudinal slot or slots, 2, therein, 1n which there is disposed a workmoving or conveying member or members,

3. The work, which for purposes of illustration is shown in the drawings as consisting of fiat bars, 4, is placed upon the hearth so that it spans the slot in which the workmoving member operates. To convey the work through the furnace in the desired manner stated above there is imparted to the work-moving member, by suitable mechanism, a series of movements as follows: the work-moving member is first raised vertically upward into contact with the work and lifts the work bodily off the stationary or work-supporting hearth; the work-moving member is then viven a longitudinal, forward movement for a short'distance carryingV with it the work which it has lifted off from the hearth: the` work-moving member is then lowered downward depositing the work upon the stationary hearth and continuing in its downward movement to be entirely out of contact'with the work; the work-moving member is next moved longitudinally backward to the place where it began its initial upward movement. This series of operations is repeated regularly and indefinitely, the work being supplied to the inlet end of the furnace and discharged or removed from the outlet end of the furnace continuously, or, if desired, the operation of the work-moving member may be stopped, after the work is in the furnace, to give the work time to be heated to the temperaturel and for the period necessary.

I am aware that conveyers intended t0 move work through furnaces b step by step movement have been proposedY but in those furnaces with which I am familiar the worl- Ymoving or conveying members are givena combined vertical and longitudinal movement instead of separate and distinct vertica'l and longitudinal movements such as I employ. My method of conveying mate- \rials through a furnace has marked advantages over the former methods for the reason that in my method the work is lifted vertically off from the hearth and the longitudinal forward movement does not commence until the work is out of contact with the hearth. In a similar manner in my method the work is deposited vertically downward upon the hearth after the longitudinal forward movement has entirely ceased. By this method of moving the work it is possible to maintain individual pieces of work in orderly and re ular spaced-apart relation to each other. his is not possible in furnaces in which the work describes cyclic or arcuate paths, in which the vertical and longitudinal movements are combined and take place simultaneously, as the surface of the hearth is always more or less uneven and the work either varies originally in shape or is warped by the heat of the furnace so that the work-moving member does not come into contact at the same time with all of the pieces of work in the furnace and consequently the pieces of work frequently become misplaced, contact with each other in the furnace, and pile up and clogthe furnace, resulting in delays and damage to the work and the furnace.

Opening out of the slots, 2, are waste gas flues, 5, which connect with other suitable ducts, 6, leading to the atmosphere or to a waste gas hood or stack, not shown, which may be provided.

The heating gases may be introduced directly into the furnace chamber, 7, or better, as shown in Figs. 3 and 6, they may be introduced into the combustion chamber, 8, and

thence passed through suitable distributing ports, 9, in the checker-work top, 10, of the furnace chamber, 7. For serving the furnace I have shown, conventionally, the gas or oil burner, 11, but it will be understood that any suitable fuel or means of heating the furnace may be employed and that any number of openings for the introduction of the' heating gases may be employed.

I prefer to construct the walls, 12, bottom, 13, and top, 14, of highly refractory materials and support the furnace upon a base such as 15, which may be of any suitable material, not necessarily highly refractory, as in the operation of my furnace the parts below' the bottom, 13, are not subjected to extremely high temperatures.

The work-moving members, 3, which are preferably made of refractory material and constitute movable sections of the hearth, 1, are carried by suitable chairs, 16, supported upon beams, v17. The refractory work-moving members, 3, are preferably constructed of a plurality of similar blocks or sections, 18, having openings, 19, extending through them.. The sections, 18, are so placed that the openings, 19, register with the flues, 5. The blocks, 18, extend downward through the slots, 2, and are made narrower than the slots so as to form clearance spaces, 20. These clearance spaces, 20, serve also as outlets for the wastey gases from the furnace chamber, 7. Longitudinal openings or slots, 21, for the supports, 16, and beams, 17, are provided in the base, 15. Other suitable chambers, such as 22, 23, 24 and 25, are provided in the base 15, for the accommodation of the operating mechanism of the workmoving members, these chambers being preferably closed to the outer atmosphere.

lt will be seen that the slots, 2, extend clear through the hearth, 1, of the furnace into the openings, 21, and that clearance spaces, 26, are provided between the workmoving members, 3, and the walls of the slots, 2, below the lues, 5.

In the operation of my furnace the gases of combustion after they have served their purpose in the furnace chamber, 7, pass downward through the clearance spaces, 20,- between the work-moving members, 3, and the walls of the slots, 2, intothe waste gas fines, 5, and thence are conducted throu h the ducts 6, to the atmosphere or stack. s the direction of flow of gases in the clearance spaces, 20, is always downward and out of the furnace chamber there is no op-v portunity for the entrance of air or cold gases through them to cool the work which is located abovel them. Should there be any leakage of cold air into the slots, 21, and clearance spaces, 26, it will be drawn into Hues, 5, and pass out through ducts, 6, with the waste gases from the furnace chamber, and will not enter the furnace chamber. Uniform heating of the work in the furnace is assured by the construction above described and chilling of the-work by the introduction of cold air through the slots, 2, cannot occur. slight plus pressure or static can be readily maintained in the work chamber, 7, of the furnace which pressure will force the gases of combustion to the flue openings, 5, in the hearth bottom. The hot gases in the outlet flues, 6, produce a draft or minus pressure at the hearth line and the combined action of the plus pressure in the work chamber and the minus pressure or flue draft produces the required circulation of the hot gases through the work chamber and out of the flues, 5. The heat from these gases uniformly heats the hearth and the work thereon.

To prevent. seepage of air into the openings provided in the foundations for the accommodationof the operatlng mechanism, covers or doors such as are shown at 27, 28

It will be understood that a` and 29 may be provided. @wing to these covers or closures a dead air space is maintained in the chambersbeneath the furnace hearth in which the metal parts of the hearth operate, which, in connection with the lue arrangement, prevents the hot gases from entering these chambers and makes it unnecessary to provide any special arrangewill be described. Crank-shaft, 33, being rotated by any suitable power connection causes the cross-beams, 30, and consequently f longitudinal beams, 17, and the work-moving member, 3, to travel longitudinally back and forth in the slots, 2, while the slot, 34, in4

the pitman, 31, permits the work-movin member to remain stationary at either en of. its travel, the time during which it is stationary depending upon the length of the slot, 34. y

'In the construction shown in Figs. l1, 2 and 3, the beams, 17, are supported by crossbeams, 30, which in turn rest upon'` longitudinal guides or bearing'plates, 35. The guides, 35, are, in turn, carried by rollers, 36, which rollers are rotatably mounted on levers,';, 37. Levers', 37, are mounted upon and secured to shafts, 38, which Vare supported in bearings, 39. The bearings, 39, are supported by thefoundation, 40. Mounted upon the shaft, `38, and securedthereto for rotation therewith are the levers, 41, to the outer ends of which is pivoted the common connecting rod, 42, which is provided with suitable length adjusting turn-buckles, 43. The connecting rod, 42, is pivoted at one end to lever, 44, which is operated by a cam, 45. For this purpose the lever, 44, iS

fulcrumed at 46, and is provided with a cam, roller, 47.- Cam, 45, is mounted upon andI- secured for rotation with shaft, 48, which shaft is geare to crank-shaft,.33, so as to rotate at the ame speed. It will be seen that cam, is soshapedthat when itis rotated by cam shaft, 48, the work-movingmember,.3, will be ralsed vertically upward during part of one revolution of the cam, 45; will be sustained in its uppermost position during another part of the revolution of the cam; will be lowered during another part of the ,revolution of the cam; and will re-v main stationary in its lower position for the last portion of the revolution of the cam.

' -The crank-pin, 32, and the cam, 45, are so located upon crank-shaft, 33, and cam-shaft, 48, respectively, that the longitudinal move- 31, to a power-driven.

ments of the work-moving member, 3, alternate with its vertical movements as follows: As seen in Fig. 7, the work-moving member, 3, is vin its forward and lower position. If now the crank-shaft, 33, be revolved in a counterclock-wise direction as seen in this figure, it will cause the pitman, 31, to draw the work-moving member toward the rear or 'right-hand end of the furnace to the position shown in Fig. 8. The cam-shaft, 48, will, at the same time revolve in a counterclock-wise direction and for a portion of its revolution the cam, 45, will not cause any vertical movement of the work-moving member. After the crank-shaft, 33, has carried its crank-pin, 32, to the right-hand end of its travel the work-moving member, 3, will remain stationary so far as the longitudinal movement is concerned while the crank-shaft revolves soas to bring the crank-pin, 32, into contact with the opposite end of its slot. During the time that there is no longitudinal movement of the work-moving member, 3, cam, 45, operates/ upon lever, 44, to lift work-moving member, 3, vertically upward to the position shown in Fi 9, by the action of the mechanism descri ed which includes the connecting rod, 42, levers, 41, shaft, 38, levers ,37, and rollers, 36. When the work-moving member, 3, has been moved to its upper position it is held there byv cam, 45, while the work-moving member, 3, is moved longitudinally forward to the position shown in Fig. 10 by the pitman, 31, operated by crank-shaft, 33, and crank-pin, 32. At the forward end of the'longitudinal movement of the work-moving member, 3, there is another rest periodfon account of the lost motion allowed between the crankpin, 32, and the pitman 31, by the slot, 34. During this rest pero cam, 45, permits the work-moving member to descend to its forward and lower position by gravity, the roller 47, of lever, 44, contacting with cam, 45, to control this lowering movement.

4 Work-moving member, 3, has now completed and carries it vertically upward; the next movement of the work-moving member which is longitudinally forward carries the work with it; the third movement of the work-moving member which .is vertically downward deposits the work upon the stationary hearth bottom; and the last movement of such a seriesaof movements of the work-moving member is to carry it longitudinally backto the place of beginning. On

account of the separation of the vertical and longitudinal movements of the work-moving member there is no opportunity for the work to drag upon the stationary hearth such as occurs where cyclic or combined vertical and longitudinal movements are imparted to the work-moving member.

To counterbalance in a large measure the weight of the work-moving member and the work, counterweights, 49, may be provided, suspended from the levers, 37, in the manner shown in Fig. 1.

ln the modified form of my invention shown in Figs. 4, 5 and 6, the flues, 50, conduct the gases of combustion from the 1ongitudinal slots in the `hearth bottom to the longitudinal ducts or flues, 5l, which are connected to up-take flues, 51a, in the end wall of the furnace. 'llhe mechanism for operating the work-movin member vertically is also somewhat mo ied in that the cross-beams, 30, are omitted and the longitudinal beams, 17, rest directly upon rollers, 52. .The rollers, 52 are carried in suitable bearings supported upon cross-beams, 53, which are given periodic vertical movements by a mechanism similar to that shown in Figs. 1,' 2-and 3, and described above. lfn the furnace shown in Figs. 4, 5 and '6, means 1s provided for opening and closing the door, 54, of the furnace in harmony with the movement of the work-moving member so that the door will be open while the work 1s being fed into the furnace and will be closed during the backward movement of the workmoving member. For this purpose the furnace door, 54, has secured to it the chains, 55, or other suitable devices, which are connected to the walking-beams, '56,

- which are pivoted upon supports, 57. The

walking-beams, 56, are connected by rods, 58, to levers, 59, and oscillate to raise and lower the door, 54, in synchronism with these levers as they are operated by the driving mechanism to raise and lower the work-moving members. lt will be seen that the door, 54, will remain closed during the backward movement of the w0rk-moving members and open during their forward movement. rfhe closing of the` door. 54, economizes heat and aids in securing uniferm heating of the work. lin the construction of the furnace shown in Figs. 1, 2 and 3, there are shown, at 60 and 61, inlet and outlet openings respectively for the work at the ends ofthe furnace while in the' construction shown in Figs. 4, 5 and 6, the outlet opening, 62, for the workis shown at one side of the furnace.

0n account ofdierent widths of work it is sometimes an advantage to be able to change the longitudinal travel of the workmoving members. For this purpose the throw of the crank which actuates 'the work- `moving member longitudinally may be varied by moving the crank-pin, 32, radially toward the center of crank-shaft, 33, to shorten the longitudinal txravel f the workmoving member or away from the center of crankshaft, 33, to lengthen* the travel. This may be done by providing holes such as are shown at 63, 64 and 65, in Fig. 4, at various distances from the center of crank diskin which the crank-pin, 32, may be secured. ln order to maintain the correct an lar relation of the shafts, 33 and 48,

lw en the position of the crank pin, 32, is

be no horizontal movement of the workmoving member. llt is also obvious that if the slot, 34, in the pitman, 31, be as long as the throw of the crank plus the diameter of pin, 32, there will be no horizontal movement of the work-moving member.

linstead of employing the several holes, `63, 64 and 65, for lchanging the throw of the crank a radial slot may be provided in the crank disk in which the crank pin may besecured at any desired distance from the center in a well known manner. ln lsuch construction it is unnecessary to alter the relative angular positions rof the shafts, 33 and 48, when making a change in the longitudinal travel of the work-moving member. Any other convenient means forI varying the vlength ofJ the longitudinal travel of the work-moving member may be employed.

ft will be understood that lf do not limit my invention t0 the particular construction which ll have illustrated. For instance, it

is obvious that shafts, 33 and 48, may be claim; p

1. ln a furnace heated by gases of combus-` tion, a heating chamber having a hearth having a longitudinal slot therein, and a work-moving member disposed in said slot, said slot being wider than said work-moving member forming clearance spaces between said work-moving member and the walls of said slot, and a flue in said hearth connected to said slot for conductinglthe waste gases of combustion away from it. f

2. In a furnace heated by gases of combustion, a heating chamber having a hearth i having a plurality of longitudinal slots therein, work-moving members disposed in said slots, said slots being wider than said work-moving members forming1 clearance spaces between said work-moving members and the walls of said slots, flues in said hearth connecting said slots and flues in said hearth connected to said slots for conducting the waste gases of combustion away from them.

3. In a heat-treating furnace in which thc articles to be treated are caused to move step by step in spaced apart relation through the work-chamber, a work-chamber provided ber being with a stationary work-supporting hearth, said hearth having a slot extending longitudinally through it, a work-moving membei' disposed in said slot adapted when operated to rst rise into contact with and lift the work vertically olf from said hearth, then to advance it a step longitudinally at a uniform height above and out of contact ywith said hearth, then to lower it vertically to rest upon said hearth the work-moving member descending out of contact with the work, and finally to return out of contact with the work longitudinally backward to the starting point, and means for operating said work-moving member.

4. In a heat-treating furnace in which the articles to be treated are caused to move step by step in spaced apart relation through the heatin chamber, a heating chamber provided wit a stationary work-supporting hearth, said hearth having a slot extending longitudinally through it, a work-moving member disposed in said slot adapted when operated to first rise into contact with and lift the work vertically off from said hearth, then to advance it a step longitudinally along but out of contact with said hearth, then to lower it vertically to rest upon ysaid hearth the work-moving member descending out of contact with the work, and finally to return out of contact with the work longitudinally backward to the starting point, means for moving said work-moving member longitudinally comprising a pitman pivoted at one end to the work-moving member and at the other end to a power-' driven crank, one end of said pitman being slotted longitudinally to vreceive its pivot to permit the work-moving member to 'rest in its longitudinal movement at each end of its travel while it is being vertically raised or lowered, and means for moving said work-moving member vertically com? prising a vertically moving support for said work-moving member, andQmea-ns operating synchronously with the rotation of said crank for raising and lowering said-l portions being spaced apart transversely of the hearth to form an openingv between them for the escape ofthe gases of combustion usedfor heating the furnace, and said opening being connected to a Waste gas line in said stationary portion of said hearth bottom adapted to conduct said gases of combustion away from the furnace.

6. A furnace conveyer comprising a work support and a work-moving member disposed side by side, said work-moving memadapted to move vertically and longitudinally relative to said work .support and means in operative engagement with said work-moving member adapted when operated 'to move said work-moving member first upward, then longitudinally vforward at a uniform height, then downward and then longitudinally backward.

7 A furnace conveyer comprising a work support and a work-moving member disposed side by side, said work-moving memer being adapted to move vertically and longitudinally relative to said work support, means connected to said work-moving member adapted when operated to impart longitudinal reciprocating motion thereto, .lifting, means connected to said Work-moving member adapted when operated to impartv vertical reciprocating motipn thereto, and mechanism connecting said irstnamed means and said lifting means whereby the longitudinal movement of said work-moving member takes place in one direction while it is at the highest point of its vertical movement and in the opposite direction while it is at the lowest point of its vertical movement. y

8. A furnace comprising a heating chainber provided with a hearth having a longitudinal Aslot therein, means for supplying heating gases/to the heating chamber, a

work-moving member disposed in said slot adapted to convey the work through said heating chamber, said slot being wider than said work-moving member forming an open- -ing between them for the escape of the gases of combustion from the heating, chamber, and means including a flue in said hearth connected to said slot for `conducting said gases of combustion away from said opening.

stationary work-supporting portion, and a movable work-moving portion disposed side` by side with a space between, them,` said work-moving portion being adapted to have vertical and longitudinal reciprocating movements relative to said work-supporting portion, means for moving said work-moving portion vertically, means for moving said work-moving portion longitudinally at a uniform height, and mechanism connecting said means whereby the vertical and 1ongitudinal movements take place in thefollowing order, vertically upward, longitudi- 5 nally forward at a uniform height, vertically downward and longitudinally backward to the place of beginning. v

10. ln a furnace a hearth bottom having a .stationary work-supporting portion, and a movable work-moving portion disposed side by side with a space between them, said work-movin portion -being adapted to have vertical and llongitudinal reciprocating movements relative to said work-supporting portion, means for moving said work-moving portion vertically, means for moving said work-moving portion longitudinally at a .uniform height, and mechanism connecting said means whereby the vertical and longitudinal movements take place in the following order, vertically upward, longitudinally forward at a uniform height, vertically downward and longitudinally backward to the `place of beginning, and a waste gas Hue in said hearth bottom connected to said space for conducting the waste gases away from the furnace..

l1. ln a furnace a hearth bottom having a longitudinal slot, a work-moving` member disposed in said slot with clearance spaces between it and the walls of said slot, said' work-moving member being adapted to convey the work longitudinally through the furnace, and a waste gas due in said hearth bottom connected to said slot. i

12. 'lhe method of conveying materials through a furnace which consists of rst placing them upon the hearth of the furnace and then advancing them through the fur- 40 nace by step .by step progression each step consisting of a vertically upward movement ed' from the hearth, a` longitudinally forwardmovementfat a uniform height above and out of Contact with the hearth, and a et vertically downward movement to the hearth.

13. ln a heat treating furnace in which the articles toqbe treated are caused to move step by step 1n spaced apart relation through the work chamber, a work-chamber provided with a stationary work-supporting hearth, sald, work-chamber having an opening at one `end for the admission of the articles to be treated, a vertically moving door adapted to close said opening, said stationary work-supporting hearth extending outward through sald opening, a work-moving member eX- tending longitudinally through said workchamber and said opening, said work-moving l member being adapted when operated to move in repeated cycles, vertically up, horizontally forward, vertically down and horizontally backward to move the work step by step through Ithe furnace, means for oper- 6 ating said workfmoving member, and means incase? connecting said operating means and` said door whereby opening and closing movements of said door are lcaused to take place respectively with the u ward and downward movements of said worli-moving member.

14. A furnace conveyer comprising a Work support and a work-moving member disposed side by side, said work-moving member being adapted to move vertically and longitudinally relative to said work support, means `for reciprocating said work-moving member longitudinally, means for reciprocating saidwork-moving member vertically, and means for varying the length of the longitudinal reciprocating movements of said work-moving member.

15'. A furnace conveyor comprisin a work support and a work-moving mem er disposed side by side, said work-moving member being adapted to move vertically and longitudinally relative to said work support, means for reciprocating said work-moving member vertically and longitudinally and means for varying the length of the longitudinal reciprocating movements without changing the lengthof the vertical reciprotating movements of said work-moving mem- 16. A. furnace conveyer comprisin a work support and a work-moving mem er disposed side by side, said work-moving member being adapted to move vertically and longitudinally relative to said work sup-port,

mechanism connected to said work nmoving member adapted when operated to 'impart separate vertical'- and longitudinal movements to said work-moving member and means for varying the extent of said longitudinal movements.

17. ln a heat-treating furnace in which the articles to be treated are caused to move step by step in spaced apart relation through the heating chamber, a heating chamber provided with a stationary work-supporting hearth, said hearthhaving a slot extending longitudinally through it, a work-moving member disposed in said slot adapted when operated to first rise into contact with and lift the work vertically 0H from said hearth, then to advance it a step longitudinally along but out of contact with said hearth, then to lower it vertically to rest upon said hearth the work-moving member descending out of contact with the work, and linally to return out of contactwith the work longitudinally backward to. the starting point', means for moving said work-moving member longitudinally comprising a pitman pivoted at one end to the work-moving member and at the other end to a power-driven crank, one end of said p itman being slotted longitudinally to receive its pivot to permit the work-moving member to restin its longitudinal movement at each end of its-travel while it is being vertically raised 0r lowered, means for varying thel longitudinal movement of said work-moving member, and means for moving said work-moving member vertically comprising a vertically moving support for said work-moving member, and means operating synchronously with the rotation of said crank for raising and lowering said support and said work-moving member during the rest periods of the work-moving member at the backward and forward limits of its travel 10 respectively.

In testimony whereof I aHiX my signature.

. HARRY P. MCCANN. 

